Hello,
To get this out of the way; thus far, I've enjoyed this saga very much and I look forward to seeing how things progress.
I have a few things to discuss. The need for velocity before jumping and the need to jump in the direction your momentum is carrying you.
Every time somebody jumps in the series, they seem to need to have some forward momentum. And given the explanation of how jumping works, it doesn't make sense. Momentum may matter after you jump, given a potential need for maneuvering, but it has little bearing on simply translating from one location in time/space to another. Given that, why are jumps all along the momentum vector?
The second thing that has been bugging me is the need to line up in a straight line for jumping toward the target. Again, given the explanation of the way that the jump tech works, it seems possible for momentum carried into the jump, to stay with the jump vessel, in whatever direction the jump was programmed to orient the vessel, post jump. Picture this. 3 objects in space, A, B, C and one jump capable ship.
If the ship is headed away from A, currently (in the books), the ship would need to create momentum prior to the jump. If the Ship jumped from A to B, the direction and momentum of the ship, prior to jumping is translated when exiting the jump at point B. To then change targets to point C, the ship currently has to execute a series of manumvers in realspace to line up with point C before commencing that jump. What confuses me is that if you can translate mass and momentum from point A to point B, wouldn't it be a minor task to change the momentum vector at the jump exit point so that the ship is already oriented at point C, thus allowing the momentum of ship pre jump to instantaneously change vectors post jump? I.E. Instead of needing to jump away and turn around, why not jump out and have the jump exit point you at your target rather than along your pre-existing vector?
The Jump drive takes you from where you are to where you are going, in no time, but to get to where you are going you need to be heading in that direction. The Jump just moves you further along then you otherwise would have traveled in no time at all.
The Jump field is a bubble around the ship which transitions the ship to the destination, in no time, but the ship still made the journey between Point A and Point B, so if you jump through a flak wall the ship gets hit. Projectiles pass into the jump field during transition (Which I take to mean that this kind of damage only happens to the front of the ship / as the projectiles would be scooped up by the forward half of the field and immediately dumped back into normal space at the arrival point while maintaining they're original momentum (Ala the debris from the Jung Battleship Pre-Alliance capture in Ep...10)
Vector changing: It takes a lot of Delta V to change the vector of a ship as big as the Aurora. When you go into a jump, you come out the other end going the same direction and velocity as when you jumped (just further away from your starting point the you otherwise would be) to change direction you then have to burn your thrusters to change the direction you are facing, and burn your mains to change your direction of travel.
What I'm saying is that you need to actually have to change you vector before you can jump a direction. This takes time. With Jump Tactics you Hit and Run. You do not take that extra 30 seconds to change vector in the hot zone, you jump clear and jump back in after you turned somewhere else.
In your example you wanted to jump A to B then jump for C. Momentum AB is the same as Momentum BC when ABC is a straight line. When they are not in a straight line, you need to change your Delta V between Jumps. Think of it like you're in a car on ice, you can face which ever way you want but you are still sliding the same direction until you get traction for your wheels. In other words firing the Jump drive a second time without changing the direction of travel will put you at D further down the path from A to B to D (with C of to the side somewhere)
What's missing from Four Islands excellent explanation, and what I think is confusing Kirel Redhand is the fact that the name "jump drive" implies a propulsive effect, which it does not have. The jump fields simply remove 'time' from the equation by slipping everything contained within into a universe in which the dimension of 'time' does not exist. The jump fields only hold for a fraction of a second at best before they collapse, reverting the ship within them back into it's own universe. This occurs because an object that exists in a universe with the dimensions of XYZ and Time cannot exist in one that does not have all of these.
So the Aurora could not effect a course change while within a jump for a number of reasons. First, they are in the jump for a mere fraction of a second, hence there would be no time available to them to make a course change, as correctly explained by Four Islands. Second all of our propulsion methods involve time. (Even rocket thrust is measured in impulse seconds.) Time is not available to exploit while in the jump, therefore no turn can be made until after a ship exits the jump.
It should also be mentioned that the Jump field itself may be what is moving and that trying to change the course of travel may result in the shredding of the Jump object as it passed outside of the Jump field over what ever distance is traveled.
This also explains why objects caught in a jump field would be transported along with the jump object (Jung battleship in Ep 10) However that effect will not be possible messure as the jump flash is quite quick and noone wants to be the test case :p
How did the asteroid do it to ram the battle platform? I know they used a once in a lifetime orbit of celestial bodies and gravity assists to get it to the core, but I can't remember them mentioning any maneuvering engines or did I miss it?
There was talk of installing multiple use deceleration thrusters on the Karuzara, on its long journey to Sol, Which were then summararilly never mentioned again(they wouldn't manuver the Rock very much so I guess they weren't mentioned because they would only help to line up the Asteroid with Gas Giants which was how they really steered it However for the instance you are talking about, the path of the Asteroid in its orbit around the Planet Earth lined up to allow for a jump into the path of the Battle platform.
The Karuzara jumped at a point in its orbit of earth where it lined up to jump straight to a point where the relative velocities of the two objects(Karuzra & BP) were such that neither of them could avoid a collision.
